Systems and methods for compressed air energy storage and control thereof

ABSTRACT

Systems, methods, and devices for energy storage are provided. A system for energy storage includes a thermomechanical-electrical conversion subsystem for converting energy formats and a mechanical and thermal storage unit for storing energy formats. The thermomechanical-electrical conversion subsystem includes a storage subsystem including a compressor and a first thermal energy exchanger and a generation subsystem including a power generator and a second thermal energy exchanger. The storage subsystem compresses a fluid to generate compressed fluid and thermal energy. The generation subsystem generates power from the compressed fluid and the thermal energy. The mechanical and thermal storage unit includes a pressure vessel for storing the compressed fluid and a thermal energy storage for storing the thermal energy generated by the fluid compression and for providing the thermal energy to the generation subsystem for generating power.

TECHNICAL FIELD

The following relates generally to energy storage and management, andmore particularly to systems and methods for compressed air energystorage for combined heat and power and control thereof.

INTRODUCTION

Large industrial and commercial facilities are energy intensivecustomers of the electrical system and can have a significant impact onpeak management of the grid. As such, in most electrical distributionsystems, there are different pricing categories for these types ofusers. This type of pricing may focus on both total energy used (kWh)and peak power demand on the system (kW). This may act as an incentivefor these sites for better energy and demand management.

Peak electricity demand charges can represent up to 30% of utilitybills. For example, Ontarians paid $11 B in 2018 for peak demand.

Energy used in facilities is primarily for lighting, motors, andoperation of equipment (electricity), conditioning of environment(electricity or gas), and thermal power used in process manufacturing(electricity or gas). Depending on the type of facility and operation,any combination of these may be used at a particular site. Havingdifferent functions, these applications usually operate and function asseparate systems, which can result in significant energy wasted in theconversion process and missed opportunity for utilization.

Systems and methods are desired that can manage, significantly reduce,and increase flexibility in electricity demand and energy intensity ofthese types of facilities.

Accordingly, there is a need for improved systems and methods forsystems and methods for energy storage, management, and use thatovercome at least some of the disadvantages of existing approaches.

SUMMARY

A system for energy storage is provided. The system includes athermomechanical-electrical conversion subsystem for converting energyformats. The thermomechanical-electrical conversion subsystem includes astorage subsystem including a fluid compressor and a first thermalexchanger and a generation subsystem including a power generator and asecond thermal energy exchanger. The storage subsystem is forcompression of a fluid to generate compressed fluid and thermal energy.The generation subsystem is for generating power from the compressedfluid and the thermal energy. The system also includes a mechanical andthermal storage unit for storing energy formats. The mechanical andthermal storage unit includes a pressure vessel for storing thecompressed fluid and a thermal energy storage for storing the thermalenergy generated by the fluid compression and for providing the thermalenergy to the generation subsystem for generating power.

The energy formats may include any two or more of electricity, thermalenergy, and pneumatic energy.

The energy formats may include electricity, thermal energy, andpneumatic energy.

The compressed fluid may be compressed air, and the energy formats mayinclude electricity and at least one of thermal energy and pneumaticenergy.

The compressed fluid may be compressed air having a pressure between 4MPa and 70 MPa.

The pressure vessel may be located above ground and may be composed ofhigh-strength steel or composite.

The pressure vessel may be located underground in a borehole.

The borehole may include a first vertical segment housing the pressurevessel and a second vertical segment housing the thermal energy storage.

The pressure vessel may include an outer casing enclosing an innercompartment for storing the compressed fluid. The outer casing may becomposed of a thermally insulating material.

The power generator may be a microturbine having a capacity range of 250kW to 25 MW.

The thermal energy storage may include at least one of an undergroundthermal energy storage using ground as storage medium, a phase changestorage, a thermo-chemical storage, and a cool thermal energy storage.

The system may include an end-use device which is fluidly connected toat least one of the thermal and mechanical storage unit and thethermomechanical-electrical conversion subsystem via a fluidtransportation subsystem. The end-use device receives an energy formatgenerated by the system.

The energy format received by the end-use device may be electricity,thermal energy, or pneumatic energy.

The end-use device may be an air treatment unit or a process heatingunit, and the energy format received by the end-use device may bethermal energy.

The end-use device may be a compressed air-powered device the energyformat received by the end-use device may be pneumatic energy.

The system may operate at a facility having a demand range of 1 MW to 5MW.

The system may include a flow transportation subsystem for fluidlyconnecting the thermomechanical-electrical conversion subsystem and themechanical and thermal storage unit and transportation of a workingfluid therebetween.

The system may include an energy management unit including a computingdevice in communication with at least one control device. The energymanagement unit may be configured to: monitor energy format demand datafor at least one energy format; determine a control operation based onthe energy format demand data; and generate control data encodinginstructions for performing the control operation, wherein the controldata, when received by the at least one control device, causes thecontrol device to perform at least one of: adjusting a flow of a workingfluid between the mechanical and thermal storage unit and thethermomechanical-electrical subsystem; and adjusting an operatingparameter of at least one of the storage subsystem and the generationsubsystem.

The compressed fluid may be compressed air, and the system may furthercomprise an electric heater for heating the compressed air after beingheated by the second thermal energy exchanger and prior to entering thepower generator.

The system may further comprise a first temperature sensor for recordinga first temperature measurement of the compressed air prior to enteringthe second thermal energy exchanger, a second temperature sensor forrecording a second temperature measurement of the compressed air afterpassing through the second thermal energy exchanger, and a control unit.The control unit receives the first and second temperature measurementsfrom the first and second temperature sensors, respectively, controlsflow of the thermal energy from the thermal energy storage to the secondthermal energy exchanger based on the first temperature measurement, andcontrols a heat output of the electric heater based on the secondtemperature measurement.

An energy management device for controlling storage and delivery of aplurality of energy formats by an energy storage system is alsoprovided. The energy storage system includes a flow transportationsubsystem fluidly connecting a storage subsystem, a generationsubsystem, a thermal energy storage, and a pressure vessel. The energymanagement device includes a memory for storing system optimizationrules. The energy management device also includes a communicationinterface configured to: receive thermal energy stored data from asensor located at the thermal energy storage, the thermal energy storeddata indicating a quantity of thermal energy stored by the thermalenergy storage; receive compressed fluid stored data from a sensorlocated at the pressure vessel, the compressed fluid stored dataindicating a quantity of compressed fluid stored by the pressure vessel;and receive energy service demand data including a first energy formatdemand and a second energy format demand. The energy management devicealso includes a processor configured to: determine operating parametersfor each of the storage subsystem, the generation subsystem, and theflow transportation subsystem based on the thermal energy stored data,compressed fluid stored data, energy service demand data, and systemoptimization rules; generate control data encoding instructions forimplementing the determined operating parameters. The communicationinterface may be further configured to transmit the control data to acontrol device of at least one of the flow transportation subsystem, thestorage subsystem, and the generation subsystem.

The operating parameters may include a valve status for a valve of theflow transportation subsystem. The valve status may be open or closed.

The generation subsystem may include a power generator. The operatingparameters may include a power generator status. The power generatorstatus may be on or off.

The storage subsystem may include a fluid compressor. The operatingparameters may include a fluid compressor status. The fluid compressorstatus may be on or off.

The first and second energy formats may be any two of electricity,thermal energy, and pneumatic energy.

The compressed fluid may be compressed air, the first energy format maybe electricity, and the second energy format may be thermal energy orpneumatic energy.

The energy service demand data further may include a third energy formatdemand.

The system optimization rules may consider at least one of reducingelectricity demand and reducing waste energy by the system.

A method of controlling an energy storage system operating at a facilityis also provided. The energy storage system inlcudes a flowtransportation subsystem fluidly connecting a storage subsystem, ageneration subsystem, a thermal energy storage, and a pressure vessel.The method includes: determining operating parameters for each of thestorage subsystem, the generation subsystem, and the flow transportationsubsystem based on thermal energy stored data indicating a quantity ofthermal energy stored by the thermal energy storage, compressed airstored data indicating a quantity of compressed fluid stored by thepressure vessel, power service demand data, second energy service demanddata, and system optimization rules. The method also includes generatingcontrol data encoding instructions for implementing the determinedoperating parameters. The method also includes transmitting the controldata to a control device of each of the flow transportation subsystem,storage subsystem, and generation subsystem.

The operating parameters may include a valve status for a valve of theflow transportation subsystem, and the valve status may be open orclosed.

The generation subsystem may include a power generator, the operatingparameters may include a power generator status, and the power generatorstatus may be on or off.

The storage subsystem may include a fluid compressor, the operatingparameters may include a fluid compressor status, and the fluidcompressor status may be on or off.

The second energy service may be a thermal energy service or a pneumaticenergy service.

The method may include receiving third energy service demand data, wherethe second energy service is a thermal energy service and the thirdenergy service is a pneumatic energy service.

The system optimization rules may consider at least one of reducingelectricity demand and reducing waste energy by the system.

Other aspects and features will become apparent, to those ordinarilyskilled in the art, upon review of the following description of someexemplary embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings included herewith are for illustrating various examples ofarticles, methods, and apparatuses of the present specification. In thedrawings:

FIG. 1 is a block diagram of a compressed air energy storage (CAES)system, according to an embodiment;

FIG. 2 is a schematic diagram of a CAES system, according to anembodiment;

FIG. 3 is a block diagram of software components of the energymanagement unit 144 of FIG. 1 , according to an embodiment;

FIG. 4 is a flow diagram of a controller logic implemented by the energymanagement unit 144 of FIG. 1 , according to an embodiment;

FIG. 5 is a flow diagram of a process flow for a power processimplemented by a CAES system, according to an embodiment;

FIG. 6 is a flow diagram of a process flow for an HVAC processimplemented by a CAES system, according to an embodiment;

FIG. 7 is a flow diagram of a process flow for a pneumatic processimplemented by a CAES system, according to an embodiment;

FIG. 8 is a flow diagram of a process flow for a CAES system designoptimization, according to an embodiment;

FIG. 9 is a schematic diagram of an energy management unit of a CAESsystem, according to an embodiment;

FIG. 10 is a block diagram of a computing device for use in a CAESsystem, according to an embodiment; and

FIG. 11 is a schematic diagram of a CAES system using electric heatingto provide rapid response, according to an embodiment.

DETAILED DESCRIPTION

Various apparatuses or processes will be described below to provide anexample of each claimed embodiment. No embodiment described below limitsany claimed embodiment and any claimed embodiment may cover processes orapparatuses that differ from those described below. The claimedembodiments are not limited to apparatuses or processes having all ofthe features of any one apparatus or process described below or tofeatures common to multiple or all of the apparatuses described below.

One or more systems described herein may be implemented in computerprograms executing on programmable computers, each comprising at leastone processor, a data storage system (including volatile andnon-volatile memory and/or storage elements), at least one input device,and at least one output device. For example, and without limitation, theprogrammable computer may be a programmable logic unit, a mainframecomputer, server, and personal computer, cloud-based program or system,laptop, personal data assistance, cellular telephone, smartphone, ortablet device.

Each program is preferably implemented in a high-level procedural orobject-oriented programming and/or scripting language to communicatewith a computer system. However, the programs can be implemented inassembly or machine language, if desired. In any case, the language maybe a compiled or interpreted language. Each such computer program ispreferably stored on a storage media or a device readable by a generalor special purpose programmable computer for configuring and operatingthe computer when the storage media or device is read by the computer toperform the procedures described herein.

A description of an embodiment with several components in communicationwith each other does not imply that all such components are required. Onthe contrary, a variety of optional components are described toillustrate the wide variety of possible embodiments of the presentinvention.

Further, although process steps, method steps, algorithms or the likemay be described (in the disclosure and/or in the claims) in asequential order, such processes, methods and algorithms may beconfigured to work in alternate orders. In other words, any sequence ororder of steps that may be described does not necessarily indicate arequirement that the steps be performed in that order. The steps ofprocesses described herein may be performed in any order that ispractical. Further, some steps may be performed simultaneously.

When a single device or article is described herein, it will be readilyapparent that more than one device/article (whether or not theycooperate) may be used in place of a single device/article. Similarly,where more than one device or article is described herein (whether ornot they cooperate), it will be readily apparent that a singledevice/article may be used in place of the more than one device orarticle.

The following relates generally to energy storage and management, andmore particularly to systems and methods for compressed air energystorage for combined heat and power and control and management thereof.

The systems and methods of the present disclosure may manage,significantly reduce, and increase flexibility of electricity demand andenergy intensity of energy-intensive facilities, such as largeindustrial and commercial facilities.

A compressed air energy storage system (“CAES”) for combined heat andpower (“CHP”) function (referred to generally as “CAES system” herein)is provided. Systems for managing operation and control of CAES systemsare also provided. Energy used in facilities is mainly for lighting,motors, and operation of equipment (electricity), conditioning ofenvironment (electricity or gas), and thermal power used in processmanufacturing (electricity or gas). Depending on the type of facilityand operation, any number of these can be used at a site. Havingdifferent functions, they may be operated and function as separatesystems which results in significant energy wasted in the conversionprocess and missed opportunities for utilization. The systems andmethods of the present disclosure recognize these problems and aredesigned to address them, such as by reducing wasted energy fromconversion and improving utilization.

In an embodiment, a CAES system is provided that includes a mechanicaland thermal storage subsystem, a thermomechanical-electrical conversionsystem, and an energy management unit. The CAES system can provideservices including power services, HVAC (cooling and heating) services,and pneumatic services. The CAES system may advantageously be configuredand used to store electricity when demand is low and generateelectricity when demand is high. The CAES system may also advantageouslybe configured to manage and control the generation, storage, and use ofa plurality of energy types using an integrated approach. This may bedone, for example, by determining when certain energy types are neededor desired based on criteria stored in computing components of thesystem, and subsequently instructing system components to performnecessary actions to bring the system into compliance with thedetermination.

Generally, the CAES system uses energy delivered to the system to run anair compressor. The energy delivered to the system may be excess oroff-peak power that is used to compress the air. The air compressorpressurizes the air and pushes or pumps the compressed air into astorage vessel for later use. At a later time, such as when there is anelectricity demand, the CAES system uses the stored air to run ageneration subsystem (e.g. gas-fired turbine generator). This mayinclude releasing the pressurized air back to the surface, heating theair, and using the air to turn a turbine, which generates electricity.

The storage vessel may be underground. The storage vessel may be anatural storage vessel, such as an underground cavern.

The system provides an integration of software and hardware controllers.Sensors may be positioned in various parts of the building which can beused by the system process as it continuously monitors the inflow andoutflow of heat and energy (electricity—compressed air). Depending onthe direction and magnitude of energy/heat required, the system can beconfigured to bring onboard or disable the related hardware to optimizethe energy balance in the system.

The structure of the compressed air storage may reduce the need todissipate the heat generated during the air compression process, whichmay make the process close to Adiabatic and Isentropic. The structureproviding this advantage may include low conductivity soil and vesselcasing (casing of the compressed air storage).

The air may be compressed during off-peak hours and the hot, pressurizedair stored in the pressure vessel.

During operating hours of the receiving facility, the system may passthe stored compressed air through a generation subsystem (e.g.microturbine) to generate onsite electricity and reduce demand.

The CAES system includes an energy management unit configured to monitorany one or more of a compressed air demand, a heat/cold demand, and anelectricity demand to optimize the flow of compressed air and distributethe air flow accordingly in order to provide a particular service tosatisfy the demand.

The system can use the stored compressed air directly in manufacturingapplications. This may reduce the loss of conversion in the system whileproviding demand management.

The term “compressed air” as used herein (also referred to as“pressurized air”) is understood to describe air kept under a pressurethat is greater than atmospheric pressure.

As used herein, the term “between”, when used in reference to a range ofvalues such as a pressure range, or when a range of values is providedmeans the range inclusive of the lower limit value and upper limitvalue, unless otherwise stated. For example, a pressure range of “4 to70 MPa” or “between 4 MPa and 70 MPa” is taken to include pressurevalues of 4.0 MPa and 70.0 MPa.

Referring now to FIG. 1 , shown therein is a system 100 for compressedair energy storage, according to an embodiment. The system 100 providescombined heat and power.

The system 100 can store heat created from compression of air during astorage process for use later in a generation process (e.g. anelectricity generation section of the cycle).

The system 100 operates at a site 102. The site 102 includes a facilityfor receiving an output of the system 100. The energy needs and demandsof the facility can be managed using the system 100.

The facility at the site 102 may include one or more facilities orbuildings. The facility may be a large industrial or commercialfacility. The facility may be a factory, a hospital, a universitycampus, a data center, a manufacturing facility (e.g. automotivemanufacturing), or a large commercial complex (e.g. a mall). Thefacility may be a building, such as a data center, which may consumesignificant amounts of energy (e.g. electricity), generate significantamounts of energy (e.g. heat), or that requires, uses, or could benefitfrom cooling services. The type and nature of the facility may determinehow the system 100, including demand management, is configured.

The system 100 may manage, significantly reduce, and increaseflexibility of electricity demand and energy intensity of the facility.

The system 100 can be designed to work with an on-site generation unit.The on-site generation unit may be a natural gas CHP system. The system100 may work with the generation unit to significantly improve overallefficiency of the generation unit by utilizing waste heat in the amicroturbine 114 to generate electricity.

Depending on the direction and magnitude of energy or heat required, thesystem 100 can bring onboard or disable certain hardware to optimize theenergy balance in the system 100.

The facility may have a demand range between 1-5 MW.

The system 100 includes a mechanical and thermal storage unit 104.

The storage unit 104 is configured to store high-pressure hot air. Theair stored by the storage unit 104 may have a pressure range of 4-70MPa. In an embodiment, the storage unit 104 may have an operatingpressure range between 20 MPa to 55 MPA. The temperature of the storedair depends on the pressure and volume of the compressed air. If theprocess is assumed isothermal, the temperature will be ambient or closeto ambient.

The mechanical and thermal storage unit 104 may be located under orabove ground.

Embodiments having the storage unit 104 located above ground may bepreferred in cases where lower pressure storage is required.

In underground embodiments, the storage unit 104 may be located in aborehole, well, cavern, or the like.

In embodiments using a borehole, the borehole is located underground.The borehole can be located almost anywhere. Geomechanical analysis canbe used to identify a preferred location and to determine the pressurerange that the borehole can withstand. The flexibility in location forthe borehole is one particular advantage of borehole embodiments of thesystem 100 and storage unit 104.

The borehole may include a thermal insulation layer facing the inside(cavity) of the borehole. The thermal insulation layer may be soil-basedor rock-based.

The choice of casing may depend on the type of material available onsiteand the operating pressure and temperature for which each unit isdesigned. Casing options may be selected based on thermal conductivityproperties and rigidity (reaction to pressure).

The low conductivity of the borehole interior (e.g. soil) may reduce aneed to dissipate heat generated during the air compression process,making the process close to Adiabatic and Isentropic.

The depth of the borehole may depend on specific geomechanics and powerrequirements of the site 102. The depth is a function of the requiredair volume in order to reach the intended energy density of the energystorage system 100. The depth of the borehole may be in the magnitude ofkilometers.

The mechanical and thermal storage unit 104 includes a thermal energystorage (“TES”) 106 and an air storage 108. The TES 106 and the airstorage 108 are fluidly connected to each other.

The TES 106 stores heat 110. The heat 110 is generated during an aircompression process performed by the system 100.

The TES 106 may be implemented as an underground thermal energy storage(“UTES”) using ground as storage medium, phase change storage (“PCS”),thermo chemical storage (“TCS”), or cool thermal energy storage(“CTES”).

The TES 106 characteristics are determined based on the intended energydensity and the required HVAC loads.

The air storage 108 includes a pressure vessel 112 for storingpressurized air 114 generated by the system 100.

The pressurized air 114 may have a pressure range of 1000-10000 psi.Other properties of the pressurized air 114 depend on volume.

The pressurized air 114 may be high pressure, hot air. The pressurized114 air may have a pressure in the range of 4-70 MPa and a temperatureof up to 650° C. The pressure vessel 112 may be an air storage tank.

The pressure vessel 112 may comprise an outer casing enclosing an innercompartment for storing the pressurized air 114. The casing may becomposed of a thermally insulating material.

An above-ground embodiment of the pressure vessel 112 may be made fromhigh-strength steel or composite. High-strength steel may be defined asdefined as steel that has yield strength ranging between 210-550 MPa anda tensile strength 270 to 700 MPa.

An underground embodiment of the pressure vessel 112 may be a borehole,drilled or otherwise made into ground, with casing (e.g. soil, steelalloy, concrete). The size range may be 50-1000 m³. The material usedfor casing and the layers may be designed to have low thermalconductivity.

The system 100 also includes a fluid transportation subsystem 116. Thefluid transportation subsystem 116 transports fluids (e.g. workingenergy fluid, hot and cold air, compressed air), such as the pressurizedair 114, throughout the system 100 including to and from various systemcomponents.

The fluid transportation subsystem 116 includes a plurality of fluidconduits 118. The fluid conduits 118 fluidly connect system componentssuch that the compressed air 114 and other fluid components can betransported throughout the system 100.

The fluid transportation subsystem 116 also includes valves 120. Thevalves 120 may include any one or more of pressure valves, flow valves,and throttling valves. The valves 120 operate to control the flow rateof fluids through the fluid conduits 118. In some cases, the valves 120may form a valve or flow control subsystem for controlling flow in thesystem. The flow control subsystem can be controlled by one or morecomputer components of the system (e.g. energy management unit 144,described below), which may include making determinations on whichvalves 120 to open or close in order to promote flow to a particularsystem component or destination to achieve a particular result (e.g.open a valve to absorb heat from environment into a fluid conduit 118).

The fluid connections between system components provided by the fluidtransportation subsystem 116 are denoted by solid arrows in FIG. 1 .

The system 100 also includes a thermomechanical-electrical conversionsubsystem 122.

The thermomechanical-electrical conversion subsystem 122 is configuredto generate thermomechanical energy from electrical energy andelectrical energy from thermomechanical energy. The conversion subsystem122 is fluidly connected to the storage unit 104 via the fluidtransportation subsystem 116.

The conversion subsystem 122 includes a storage subsystem 124 and ageneration subsystem 126.

The storage subsystem 124 compresses ambient air to generate hot,pressurized air 114. The pressurized air 114 is stored in the pressurevessel 112.

In an embodiment, the storage subsystem 124 includes a compressor 128and a heat exchanger 130.

The compressor 128 is fluidly connected to the air storage 108 via thefluid transportation subsystem 116 such that compressed air 114generated by the compressor 128 can be provided to and stored in thepressure vessel 112.

The heat exchanger 130 is fluidly connected to the thermal energystorage 106 via the flow transportation subsystem 116.

The storage subsystem 124 is configured to receive storage processinputs. The storage subsystem 124 uses the storage process inputs togenerate compressed air 114 and heat 110, which can be stored by thecompressed air storage 108 and thermal energy storage 106, respectively.

The storage process inputs include ambient air and power. The ambientair and power are used by the compressor 128 to generate the compressedair 114, which can be transported via the fluid transportation system116 for storage in the compressed air storage 108.

The storage subsystem 124 is configured to generate storage processoutputs. The storage process outputs include the pressurized air 114 andheat 110. The storage process outputs can be stored by the compressedair storage 108 and thermal energy storage 106 for later use by thesystem 100.

The generation subsystem 126 generates electricity using the compressedair 114 from the compressed air storage 112.

The generation subsystem 126 includes a heat exchanger 132 and a turbinegenerator 134.

The turbine 134 may be a microturbine. The microturbine may be a compactform of a conventional gas turbine which may have a capacity range of250 kW to 25 MW.

The generation subsystem 126 is configured to receive generation processinputs, which are used by the generation subsystem 126 to generategeneration process outputs. The generation process inputs include heat110 and compressed air 114. Using the heat 110 and compressed air 114,the generation subsystem 126 generates generation process outputsincluding electricity that can be used by the facility at the site 102.

The electricity can be delivered from the generation subsystem 126 to anend-use device for consumption.

The system 100 also includes an HVAC subsystem 136 and a pneumaticsubsystem 138.

The HVAC system 136 includes an HVAC unit 140. The pneumatic subsystem138 includes a pneumatic end-use device 142.

The HVAC subsystem 136 and pneumatic subsystem 138 are fluidly connectedto other system components, such as the conversion subsystem 122 and thestorage unit 104 via the fluid transportation subsystem 116.

The HVAC subsystem 136 provides cooling and heating services to thefacility. The HVAC subsystem 136 can provide the cooling and heatingservices by interacting with the storage unit 104 and conversionsubsystem 122. For example, the quantity of heat 110 flowing to the TES106 may be adjusted to add or remove heat to or from the environment ofthe facility to provide a heating service or cooling service,respectively.

During warmer months of the year, the system 100 may implement ageneration process via the generation subsystem 126 to reduce demand onthe HVAC subsystem 136, as the expansion of the pressurized air 114 canresult in a drop in temperature. Conversely, during the cooler months ofthe year, the system 100 can use heat 110 generated during thecompression process (i.e. by storage subsystem 124) to heat the facility(e.g. preheat the facility in the early hours of the day).

The pneumatic subsystem 138 provides pneumatic (or compressed air)services to the facility. In particular, the pneumatic subsystem 138 canprovide the compressed air 114 to pneumatic end-use device 142. Thepneumatic end-use device 142 can use the compressed air 114 to power theend-use device 142. For example, the end-use device 142 may be an airtool or the like that uses compressed air to operate. The provision ofpneumatic services may include transporting the compressed air 114 fromthe pressure vessel 112 to the pneumatic end-use device 142 via thefluid transportation subsystem 116 in a manner that bypasses thegeneration subsystem 126 (which may, under normal circumstances, use thecompressed air 114 to generate power).

The compressed air 114 can be used directly in manufacturingapplications, which can reduce the loss of conversion in the system 100while providing demand management. For example, the heat generatedduring air compression in facilities is normally wasted (dissipated).Advantageously, the system 100 can capture and store this heat (e.g.heat 110) in the TES 106. As a result, the system 100 can increase, insome cases significantly, the conversion efficiency and reduce theenergy losses in the compression process.

The system 100 also includes an energy management unit 144. The energymanagement unit 144 manages the operation of the components of system100.

The energy management unit 144 is communicatively connected to thestorage unit 104, conversion subsystem 122, fluid transportationsubsystem 116, HVAC subsystem 136, and pneumatic subsystem 138 via anetwork. The network may be a LAN or a WAN and may include wireless orwired components.

Data communications between the energy management unit 144 andcomponents 104, 122, 116, 136, and 138 are denoted in FIG. 1 by dashedlines.

The energy management unit 144 is configured to analyze system data anddetermine an optimum output for the system 100. The optimum output mayinclude flow parameters and component configurations. The optimum outputmay be one that reduces power demand for the facility and/or reduceswaste energy. The optimum output includes system parameters andconfigurations that consider and utilize the flow and operation of othersystem components.

The energy management unit 144 includes a computing device 146 (orenergy management device), sensors 148, and control equipment 150. Thecomputing device 146 runs software 152 comprising instructions formanaging and controlling the operation of system 100 and its components,such as described herein. The control equipment 150 includes one or morecontrol devices.

The computing device 146 may be a single computing device, such as aserver, or a plurality of computing devices. The computing device 146may be located at the site 102 or at another location. In some cases,the computing device 146 may include onsite and offsite components incommunication with one another. For example, the computing device 146may include a remote or cloud server in communication with one or moreonsite components.

The computing device 146 is communicatively connected to the sensors 148and the control equipment 150 via a network. The network may be a LAN orWAN. The network may include wired or wireless components.

The sensors 148 are configured to acquire sensor data. The sensor datais transmitted by the sensors 148 to the computing device 146, where thesensor data can be analyzed via the software 152 to determine how thesystem 100 should operate, including how air and other fluid componentsshould flow through the system 100. The sensor data may include any oneor more of power sensor data, HVAC sensor data, and pneumatic sensordata. The sensors 148 may be positioned around the site 102, includingat or in any one or more of system components 104, 122, 116, 136, and138. The sensors 148 continuously monitor inflow and outflow of heat 110and energy (e.g. electricity—compressed air).

The software 152 may be configured to receive the sensor data from thesensors 148 (as well as any additional non-sensor data inputs), analyzethe received sensor data, and determine an optimized flow and airdistribution for the system 100. The optimized flow and air distributioncan be stored as system control data at the computing device 146. Thesoftware 152 can communicate, via the computing device 146, determinedcontrol instructions to the control equipment 150.

The computing device 146 stores system optimization rules in a memory.The system optimization rules may be implemented via the software 152.The system optimization rules may be designed to consider reducingenergy demand and/or waste energy. Certain data received or stored bythe computing device 146 may be analyzed by the software 152 in light ofthe system optimization rules. Such data may include, for example,sensor data and service demand data (e.g. power service demand data,thermal energy demand data, etc.). Sensor data may include dataindicating how much compressed air and heat are stored in the pressurevessel 112 and TES 106, respectively. Service demand data may indicate ademand level for a particular energy service (e.g. power/electricity,thermal energy, pneumatic energy) at the facility. This may includedemand from end-use units such as air treatment units, tools or systemspowered by compressed air, process heating units, and devices powered byelectricity.

The control equipment 150 is configured to receive the system controldata and perform a control operation according to the received systemcontrol data. The system control data may include or encode instructionsto be carried out by the control equipment 150. For example, the controlequipment 150 may activate (e.g. bring online) or inactivate (e.g.disable) certain components based on received system control data. Thecontrol equipment 150 is configured to adjust the flow of fluidcomponents in the system, for example by controlling the fluidtransportation subsystem 116 via the valves 120. Depending on the natureof the received system control data, the control equipment 150 may alterflow to or from TES 106 or air storage 108, for example, via controllingvalves 120 of the fluid transportation system 116.

In some cases, the system control data generated by the software 152 andprovided to the control equipment 150 may instruct the control equipment150 to initiate or stop a process, such as a storage or generationprocess of the conversion subsystem 122, or activate or inactivate acomponent such as the compressor 128 or turbine 134.

The system 100 can provide valuable services for commercial electricityfor end users. The services include electrical energy, which can be usedduring peak times, thermal energy, which can be used for theconditioning of the facility environment (cooling and heating), andcompressed air, which can be used by air-powered equipment. The thermalenergy service capability and compressed air service capability of thesystem 100 provide advancement over existing CAES systems. The abilityof the system 100 to provide electrical energy, thermal energy, andcompressed air service capabilities provides advancement over otherenergy storage technologies.

The energy management unit 144 may be configured to maximize round-tripefficiency by intelligently managing the inflow and outflow of energy inall formats (e.g. electricity, thermal, compressed air), which mayincrease total energy utilization. The energy management unit 144 mayalso optimize the operation of the energy storage system 100 and itsintegration with the electrical grid and existing air-generation andHVAC systems at the facility.

Referring now to FIG. 2 , shown therein is a schematic of an embodiment200 of the CAES system 100 of FIG. 1 . The CAES system 200 representsone possible embodiment of system 100 of FIG. 1 .

The mechanical and thermal storage unit 104 of CAES system 200 includesthermal energy storage (TES) 204 and pressure vessel 208.

The thermomechanical-electrical conversion system 122 of the CAES system200 includes heat exchanger 212, compressor 216, pre-heater 220, andgenerator 224.

The compressor 216 can receive ambient air and power and generatecompressed air 114. The compressor 216 may include an integrated heatexchanger which may channel heat into the energy flow system (e.g. intoair flow lines of the system, such as fluid conduit 118) instead ofdissipating the heat.

The heat exchanger 212 captures heat 110 generated from the compressionprocess performed by the compressor 216. The heat 110 is transferred viathe fluid transportation subsystem 116 to the TES 204, where the heat110 is stored for later use. The heat exchangers for the energyconversion unit are integrated into the TES unit 204 and are locatedbetween the compressor 216, preheater 220, and pressure vessel 208.

The pre-heater 220 preheats pressurized air 114 that has been releasedfrom air storage 208 prior to the air being provided to the generator224. In doing so, the system 200 can avoid using gas to preheat the airfor the generation process. The control valve unit 236 is part ofpreheater 220 and is positioned between process heating unit 244, directcompressed air output 246, generator 224, and air treatment unit 240 tocontrol the flow of heat from these units to the fluid (air). Thepreheater 220 is also a heat exchanger that is placed between the airtreatment unit 240, generator 224, direct compressed air output 246, andprocess heating unit 244.

The generator 224 receives the preheated pressurized air 114 andgenerates electricity from the preheated, pressurized air 114. Thegenerator 224 may have its own integrated heat exchanger that isnecessary for its function. However, instead of dissipating the heat, itis channeled into the energy flow system (mainly the air flow lines,e.g. 118).

The energy management unit 144 of CAES system 200 includes powermanagement device 228, controller 232, control valve 236, as well assoftware 152 (not shown) configured to run on power management device228 and operate control equipment such as controller 232 and controlvalve 236 in order to control flow in the system 200 and storage andgeneration of energy. The controller 232 controls the flow of air andthe heat exchange between TES 204 (and, by extension, pressure vessel208), compressor 216, and preheater 220. Control valve 236 is part ofthe preheater unit 220 to control the heat and air flow between processheating unit 244, direct compressed air output 246, generator 224, andair treatment unit 240. Control valve 236 distributes heat and airwithin these units based on the commands received from power managementdevice 228 to optimize the output and total energy efficiency.

The system 200 also includes an air treatment unit 240. The airtreatment unit 240, also known as an air handling unit (“AHU”), is theintegration point with the existing HVAC system in the facility. The airtreatment unit 240 aims to capture and store the waste heat of thefacility in the TES 204, or treat the air for air-conditioning purposes.The air treatment unit 240 may operate as an air handler to regulate andcirculate air as part of a heating, ventilating, and air-conditioningsystem. The air treatment unit 240 may be a large metal box containing ablower, heating or cooling elements, filter racks or chambers, soundattenuators, and dampers. The air treatment unit 240 may connect to aductwork ventilation system at the facility that distributes theconditioned air through the facility and returns it to the air treatmentunit 240. In some cases, the air treatment unit 240 may discharge(supply) and admit (return) air directly to and from the space served bythe unit 240 without ductwork. The air treatment unit 240 may have itsown integrated heat exchanger that is necessary for its function.However, instead of dissipating the heat, it is channeled into theenergy flow system (mainly the air flow lines, e.g. 118).

The system 200 also includes a process heating unit 244. The processheating unit 244 represents functions or equipment within a givenfacility that use or produce heat as part of their process (e.g. ovens).The process heating unit 244 interacts with the rest of the system 200by the way of preheater 220 and control valve 236. Depending on theavailability and requirement at any point during the operation, excessheat from the processes of the process heating unit 244 can be capturedby the system 100 and utilized for a heating function in another unit,or the excess heat from other functions may be captured by the system100 and used to reduce the thermal energy needed in the processes ofprocess heating unit 244. For example, the system 200 may direct theflow of heat to and from the TES 208 to either store excess heat fromthe process heating unit 244 or deliver heat (captured elsewhere by thesystem) to the process heating unit 244. Flow determinations can be madeby the power management unit 228. Process heating unit 244 may includeits own integrated heat exchanger that is necessary for its function.However, instead of dissipating the heat, the heat is channeled into theenergy flow system (mainly the air flow lines, e.g. 118).

The system 200 can provide a direct compressed air output 246 from thefluid transportation subsystem 116. The direct compressed air output 246includes pressurized air 114 from the pressure vessel 112 that isdischarged and bypasses the generation subsystem 126 so that thepressurized air 114 can be used by the pneumatic subsystem 138, and inparticular the pneumatic end-use unit 142.

The fluid conduits 118 of the fluid transportation subsystem 116 fluidlyconnect the compressor 216, heat exchanger 212, thermal energy storage204, pressure vessel 208, preheater 220, generator 224, process heatingunit 244, air treatment unit 240, and end use device 142 (not shown inFIG. 2 ) that receives the direct compressed air output 246.

Referring now to FIG. 3 , shown therein is a block diagram of softwarecomponents 300 for use in a CAES system such as system 100 of FIG. 1 ,according to an embodiment.

The software components 300 may be software components of software 152of FIG. 1 . The software components 300 may be implemented as one ormore software modules that, when executed by an executing device (e.g.computing device 146 of FIG. 1 ), cause the executing device to performthe actions, functions, and operations described herein.

As described in reference to FIG. 1 , energy management unit 144includes software 152. Generally, the software 152 may control, incooperation with other components of the energy management unit 144, themanagement of energy in the system 100. The management of energyincludes the storage and use of compressed air 114, such as to generatepower for use by the facility, and the control of air flow throughoutthe system 100 to achieve the desired operation.

The software 152 includes a system control module 302. Generally, thesystem control module 302 determines and controls the flow of airthroughout the system 100. By determining and controlling the flow ofair, the system control module 302 can control and manage how the air isused, including how and when compressed air 114 is stored and dischargedand what output is generated from the discharge of the compressed air114.

The system control module 302 receives sensor data from sensors 148 andanalyzes the received data to determine system output control data.

The system control module 302 detects a type and amount of energy usedby primarily end-use units at the facility and utilizes the flow andoperation of components of the system 100 for optimum output. The system100 may provide three main services for the facility at the site 102including electricity, heating/cooling, and compressed air. As a result,the system 100, for example via the energy management unit 144,continuously monitors the balance of the three services in the facility.The system 100 can store the service outputs in the system 100 orprovide the service outputs to the facility based on a shortage orexcess of each service output. As the system 100 manages the balance ofelectricity, HVAC load, and compressed air in the whole facility, theoutput can be optimized by the system 100 in order to minimize energycosts and reduce total energy loss (utilization) while also ensuringreliable and continuous operation of the facility. The system controlmodule 302 may reduce power demand and reduce waste energy. The systemcontrol module 302 monitors demand for compressed air, heating/cooling,and electricity to optimize flow and distribute air flow accordingly.

The system control module 302 may instruct and control system 100components to compress air during off-peak hours.

The system control module 302 may instruct and control generation ofonsite electricity from compressed air to reduce demand. The systemcontrol module 302 may do so by generating electricity during facilityoperating hours.

The system control module 302 may reduce loss of conversion in thesystem 100 and provide demand management.

The system control module 302 receives and analyzes data related to theinflow and outflow of heat and energy.

The system control module 302 includes a power process module 304, anHVAC process module 306, and a pneumatic process module 308. Invariations, the system control module 302 may include any one or more ofmodules 304, 306, 308 depending on the types of services the system 100is configured to provide.

The power process module 304 implements a power process (e.g. process500 of FIG. 5 , below). The power process module 304 controls theoperation of the power subsystem including the mechanical and thermalstorage unit 104 and the thermomechanical-electrical conversionsubsystem 122, as well as the fluid transportation subsystem 116responsible for transporting air flow throughout the power subsystem.

The HVAC process module 306 implements an HVAC process (e.g. process 600of FIG. 6 , below). The HVAC process module 306 can implement a coolingor heating process for provision of cooling and heating services to thefacility, respectively. The HVAC process module 306 determines how theHVAC subsystem 136 interacts with the power subsystem.

In particular, the HVAC process module 306 may be configured to identifyopportunities for engaging with the storage and generation processes ofthe power subsystem in order to operate the system 100 most efficiently.One such example is the storage or use of compressed air 114 in order tolower or raise the temperature of the environment of the facility.

The pneumatic process module 308 implements a pneumatic process (e.g.process 700 of FIG. 7 ). The pneumatic process module 308 may controlthe provision of pneumatic services to the facility via the pneumaticsubsystem 138. The pneumatic process module 308 determines how thepneumatic subsystem 138 interacts with the power subsystem.

In particular, the pneumatic process module 308 may be configured toidentify opportunities for engaging with the generation process of thepower subsystem (i.e. the discharge of compressed air 114 from airstorage 108) in order to operate the system more efficiently. In anexample, the pneumatic process module 308 may engage the power subsystemand use compressed air discharged from air storage directly as input toend-use devices 142 that use compressed air (e.g. air tools inmanufacturing).

Referring now to FIG. 4 , shown therein is a flow diagram of acontroller logic process flow 400, according to an embodiment. Theprocess flow 400 may be implemented by the energy management unit 144 ofFIG. 1 , for example by software 152.

Generally, the process flow 400 can be used to control the operation ofand interaction between the various subsystems of the CAES system 100,including a power subsystem, an HVAC subsystem, and a pneumaticsubsystem. In variations, the system 100 may include only one or two ofthese subsystems. In such variations, the process flow 400 can beadjusted accordingly to control the operation of and interaction betweenthe applicable subsystem or subsystems.

The process flow 400 includes a plurality of data inputs including HVACsensor data 402, power sensor data 404, and pneumatic sensor data 406.The sensor data 402, 404, 406 The data inputs also include operationplanning input data 408 (e.g. plant operation scheduling input plan) anda pricing/costing data input (not shown). The operation planning inputdata 408 may include, for example, any one or more of a productionschedule, an air-conditioning schedule, facility operation hours, andeach energy carriers cost factors and structure (e.g. time of use).

The sensor data inputs 402, 404, 406 may be received from sensors 148 ofthe respective subsystems (e.g. HVAC sensor data 402 received from HVACsubsystem sensors) and stored in memory of the computer device 146. Theoperation planning input data 408 and pricing data input are also storedin memory.

At 410, the data inputs 402, 404, 406, 408 are merged and sorted. Themerging and sorting may be performed by a data merging and sortingmodule implemented by the software 152. The merging and sorting 410generates merged and sorted data. The merged and sorted data is storedin memory.

At 414, system output control data is computed from the merged andsorted data. The system output control data may be computed via adecision-making unit which is a component of the software 152 (e.g.system control module 302). The decision-making unit is configured todetermine an optimized output of the system 100 based on the input datacoming from data merging and sorting module of 410. The decision-makingunit commands and controls power, pneumatic and HVAC units in the system100. The system output control data is computed by the energy managementunit 144 and stored in memory.

The system output control data is transmitted and provided as input toan HVAC subsystem 416, a power subsystem 418, and a pneumatic subsystem420. Each of the subsystems 416, 418, 420 receives a subset of commands(i.e. system output control data) that is associated with that specificsubsystem. In other embodiments, the system 100 may be designed suchthat one or more of subsystems 416, 418, 420 receives the completesystem control output data (as opposed to a subset relevant to thesubsystem). For each of subsystems 416, 418, 420, the system outputcontrol data may be received by a control component or computing deviceof the subsystem in communication with one or more physical componentsof the subsystem such that the actions and operation of the subsystemcan be controlled according to the system output control data. Thereceiving control component may be located at or in close proximity tothe controlled physical components of the subsystem.

Each of the subsystems 416, 418, and 420 are configured to providesubsystem services. The subsystem services can be used by the facility.For example, the HVAC subsystem 416 can provide heating services andcooling services, the power subsystem 418 can provide electricityservices, and the pneumatic subsystem 420 can provide pneumatic orcompressed air services. In some cases, as described below, subsystemservices of a first subsystem may be required or used to providesubsystem services of a second subsystem. In an example, the HVACsubsystem 416 may, based on the system output control data at 414, berequired to provide a heating service. To provide the heating service,the HVAC subsystem 416 may require the services of another subsystem,such as the power subsystem 418, and may engage the power subsystemservices to do so.

At 422, based on the received system output control data from 414, adetermination is made as to whether other services, such as powerservices or pneumatic services, are required by the HVAC subsystem 416.FIG. 4 describes the logical process of the energy management unit 144,which may include analysis and decisions made based on the total datainput from all units and the operational requirement of thefacility/site. The decision tree may be configured to respond to theinput from all sensors 148 on a continuous basis. These sensors 148 mayindicate what types of service is require at any particular point intime and the availability of resources.

The other services required determination at 422 is performed by thesoftware 152 of the energy management unit 144. Decision-makingalgorithms embedded within the software 152 are configured to determinewhether additional services are required based on the input from theintegrated sensors of the control units.

If it is determined that a power subsystem service is required, at 424the HVAC system 416 can engage the power subsystem 418. The powersubsystem 418 can then provide the required services.

If it is determined that a pneumatic subsystem service is required, at426 the HVAC system 416 can engage the pneumatic subsystem 420. Thepneumatic subsystem 420 can then provide the required services.

At 428, based on the received system output control data from 414, adetermination is made as to whether other services, such as HVACservices or pneumatic services, are required by the power subsystem 418.FIG. 4 describes the logical process of the energy management unit 144,which may include analysis and decisions made based on the total datainput from all units and the operational requirement of thefacility/site. The decision tree may be configured to respond to theinput from all sensors 148 on a continuous basis. The sensors 148indicate what types of service is required at any particular point intime and the availability of resources. The type of service required maydepend on the needs of the facility which can be compressed air,heating/cooling, and/or electricity.

The other services required determination 428 may be performed by thecomputing device 146 or a controller component of the power subsystem418.

If it is determined at 428 that an HVAC subsystem service is required,at 430 the power subsystem 418 can engage the HVAC subsystem 416. TheHVAC subsystem 416 can then provide the required services.

If it determined at 428 that a pneumatic subsystem service is required,at 432 the power subsystem 418 can engage the pneumatic subsystem 420.The pneumatic subsystem 420 can then provide the required services.

At 434, based on the received system output control data from 414, adetermination is made as to whether other services, such as HVACservices or power services, are required by the pneumatic subsystem 420.FIG. 4 describes the logical process of the energy management unit 144,which may include analysis and decisions made based on the total datainput from all units and the operational requirement of thefacility/site. The decision tree may be configured to respond to theinput from all sensors 148 on a continuous basis. The sensors 148indicate what types of service is required at any particular point intime and the availability of resources. The type of service required maydepend on the needs of the facility which can be compressed air,heating/cooling, and/or electricity.

The other services required determination 434 may be performed by thecomputing device 146 or a controller component of the pneumaticsubsystem 420.

If it is determined at 434 that an HVAC subsystem service is required,at 436 the pneumatic subsystem 420 can engage the HVAC subsystem 416.The HVAC subsystem 416 can then provide the required services.

If it is determined at 434 that a power subsystem service is required,at 438 the pneumatic subsystem 420 can engage the power subsystem 418.The power subsystem 418 can then provide the required services.

At 440, an HVAC process is initiated. The performance of the HVACprocess is based on the system output control data 414 and thedetermination 422.

The HVAC process 440 includes the provision of cooling or heating forthe facility. The HVAC process 440 may engage with the power dischargeor power charge process of the power process 442. Engaging the powerprocess 442 can allow for the use of the charge (storage) process ordischarge (generation) process to introduce or remove heat from theenvironment of the facility.

At 442, a power process is initiated. The performance of the powerprocess is based on the system output control data 414 and thedetermination 428.

The power process 442 includes storage of energy as compressed air 114and generation of electricity from the stored compressed air 114. Theelectricity can be used by the facility.

At 444, a pneumatic process is initiated. The performance of thepneumatic process is based on the system output control data 414 and thedetermination 434.

The pneumatic process 444 includes providing compressed air to end useunits that consume or use compressed air in their operation (e.g.manufacturing applications, tools). The pneumatic process 444 may engagewith power process 442, such as to use compressed air 114 released fromcompressed air storage 108 as a compressed air input to a compressedair-powered end unit. The pneumatic process 444 may include thedischarge of the compressed air and bypassing the generation subsystemof the power subsystem where, during the power process, the compressedair is provided as input to the turbine generator to generate poweroutput.

At 446, the required processes 440, 442, 444 are performed andcompleted.

At 448, the process flow 400 ends.

Referring now to FIG. 5 , shown therein is a process flow 500 for apower process implemented by a CAES system, according to an embodiment.The CAES system may be the CAES system 100 of FIG. 1 .

The process flow 500, or portions thereof, may be implemented by theenergy management unit 144 of FIG. 1 , and in particular, by software152. The process flow 500 may be implemented as one or more softwaremodules that, when executed, cause the executing device to perform theactions, functions, and operations described by the process flow 500.

The process flow 500 may be the power process 442 of FIG. 4 , or aportion thereof. The process flow 500 is performed by the powersubsystem 418 based on input from the energy management unit 144. Theenergy management unit 144 is configured to process data and controlactions, operations, and outputs of the physical components of the powersubsystem 418 (e.g. storage subsystem 124 and generation subsystem 126).

The power subsystem 418 receives electricity input system data 504,which may be stored in memory of computing device 146. The electricityinput system data 504 may be collected from any electricity inputsystem, which may include onsite generation (e.g. solar, wind, etc.).The onsite generation may be an off-grid system or grid-connectedsystem. The electricity input system data 504 may include electricitydemand/generation data taken from all the systems in the facility (inputand output) and the electricity coming to the facility from any of thesesources. The electricity input system data 504 is provided as input tothe process flow 500. The electricity input system data 504 may includegrid data. The electricity input system data may include any one or moreof supply data, demand data, and pricing data. The electricity inputsystem data 504 may include values in kW or MW.

The electricity input system data 504 or subsets thereof may becollected from available public-access databases or specific dataservices, for example through an exclusive API embedded within themanagement software 152 of the energy management unit 144. It should benoted that while the term “grid data” may be used, the system 100 ismainly designed to be used in behind the meter energy storageapplications. The term “electricity input system data” as used hereinsimply refers to an electrical demand profile data of the facility inwhich the systems and methods of the present disclosure are beingemployed.

The energy management unit 144 uses the electricity input system data504 to perform a supply-demand determination. The supply-demanddetermination includes comparing the supply data (i.e. a supply value)and demand data (i.e. demand value). Depending on the outcome of thedetermination, the energy management unit 144 instructs the powersubsystem to perform certain steps of the process flow 500.

At 508, if the supply data is greater than the demand data, the powersubsystem 418 initiates a storage process 510. The storage process 510includes the compression of air and storage of the resulting compressedair for later use in power generation.

At 512, if the supply data is equal to the demand data, the powersubsystem 418 initiates a shut down or idle process 514.

At 516, if the supply data is less than the demand data, the powersubsystem 418 initiates a generation process 518. The generation process518 includes the discharge of compressed air from storage and use of thecompressed air in power generation.

For the storage process 510, at 520, the energy management unit 144compares a (supply-demand) power value and a compressor minimum powervalue.

The (supply-demand) power value and the compressor minimum power valueare stored in memory of the energy management unit 144. The energymanagement unit 144 calculates the (supply-demand) power value using theelectricity input system data 504. The compressor minimum power valuemay correspond to the power required to operate the compressor of thestorage subsystem 124 which is used to compress air for storage.

If the (supply-demand) power value is less than or equal to thecompressor minimum power value, the energy management unit 144 initiatesa shut down or idle process 514 of the power subsystem 418. The basis ofthis determination by the energy management unit 144 is that there isnot enough available excess energy (Power*Duration) to run thecompressor. This situation may also happen when neither morecompressed-air storage nor power generation is required.

If the (supply-demand) power value is greater than the compressorminimum power value, the power subsystem # turns the compressor on at524. Turning the compressor 524 on may include the energy managementunit 144 sending a signal to the compressor 524 to turn the compressor524 on.

The active compressor 524 receives power 526 and ambient air 528 asinputs to a compression process. The compressor 524 uses the power 526to compress the ambient air 528 to generate compressed air 333.

A heat exchanger 530 is used to capture heat 532 generated as abyproduct of the compression process performed by the compressor 524.

The compressed air 533 is transferred to an air storage tank 534 via afluid transportation subsystem (e.g. fluid transportation subsystem 116of FIG. 1 ). The air storage tank may be located underground. In anembodiment, the air storage tank is a cavern. The air storage tank 534stores the compressed air 533 for later use, such as by the powersubsystem 418 (e.g. in generation process 518).

The heat 532 captured by the heat exchanger 530 is passed to a thermalstorage unit (TES) at 538. The thermal storage unit 538 stores the heat532 for later use, such as by the power subsystem 418 in generationprocess 518.

Referring now to the generation process 518, at 550, the energymanagement unit 144 compares a heat-energy (TES) value and a minimumheat required value. The heat-energy value and the minimum heat requiredvalue are stored by the energy management unit 144 (in memory). Theheat-energy (TES) value is the heat stored in the TES. The energymanagement unit 144 is configured to constantly compare the heat-energy(TES) value with the minimum heat required value in order to decide onthe outputs required to keep the system in balance. For example, if theminimum heat required is more than the heat-energy (TES) value, moreheat should be generated or captured via waste-heat recovery at the airhandling unit (e.g. air treatment unit 240 of FIG. 2 ). Otherwise, thesystem may not be able to operate at that point in time.

The heat-energy value may correspond to an amount of heat stored and/oravailable in the thermal storage unit 538. The heat-energy (TES) valuerepresents the amount of heat energy (e.g. in eKWh) stored in the TES.The heat-energy value data may be acquired and provided to the energymanagement unit 144 by a sensor 148 of the thermal storage unit 538.

The minimum heat required value may correspond to the minimum amount ofheat required to preheat the compressed air 533 prior to inputting thecompressed air 533 into the generation subsystem 126 (i.e. the turbine544 below). The minimum heat required value may correspond to theminimum heat required to increase the temperature of the compressed airprior to its entrance to the turbine to produce electricity withoutcausing freezing due to the temperature drop as a result of airexpansion.

If the heat-energy (TES) value is not greater than the minimum heatrequired value (i.e. less than or equal to), the power subsystem 418initiates the shutdown/idle process 514.

If the heat-energy (TES) value is greater than the minimum heat requiredvalue, the energy management unit 144 performs another determination at552.

At determination 552, the energy management unit 144 compares a cavernair pressure value and a minimum air pressure required value.

The cavern air pressure value may correspond to the air pressure of thepressurized air 533 stored in the air storage tank 534. The cavern airpressure value represents the steady pressure of the air stored in thestorage. The cavern air pressure value data may be acquired and providedto the energy management unit 144 by a pressure sensor 148 of the airstorage tank 334.

The minimum air pressure required value may correspond to the minimumair pressure required to operate the turbine generator 544. The minimumair pressure required value represents the compression level or thepressure of air required to meet the intended energy density. Theminimum air pressure required value may be stored at the energymanagement unit 144.

If the cavern air pressure value is not greater than the minimum airpressure required value (i.e. less than or equal to), the system 100initiates the shutdown/idle process 514.

If the cavern air pressure value is greater than the minimum airpressure required value, the power subsystem 418 continues with thegeneration process 518 and turns on turbine generator 544.

The turbine 544 receives as input the compressed air 543 from the airstorage tank 534. The compressed air 543 is provided from the airstorage tank 534 to the turbine 534 via the fluid transportationsubsystem 116.

Prior to the turbine 544 receiving the compressed air 543, thecompressed air 543 may be preheated using a heat exchanger 542 and heat540. The heat 540 is provided by the thermal storage unit 538 and istransferred to the heat exchanger 542 using the fluid transportationsubsystem 116. The heat exchanger 542 uses the heat 540 to preheat thecompressed air 543 form storage tank 534 prior to the compressed air 543entering the turbine 544. Accordingly, the heat exchanger 542 transfersthe preheated compressed air 543 to the turbine 544 via the fluidtransportation subsystem 116.

As described, the active turbine 544 receives the preheated compressedair 543 from the heat exchanger 542 and generates power/electricity 546and air 548. The air 548 is a byproduct that can released to theenvironment (i.e. low pressure, expanded air on the outflow side of theturbine 544).

The power 546 can be used by a facility, such as a facility at site 102of FIG. 1 , to power various devices and processes. The power 546 canalso be used in other processes implemented by the CAES system 100, suchas an HVAC process (e.g. HVAC process 600) or a pneumatic process (e.g.pneumatic process 700).

Referring now to FIG. 6 , shown therein is a process flow 600 for anHVAC process implemented by a CAES system such as system 100 of FIG. 1 ,according to an embodiment. The process flow 600 may be the HVAC process440 of FIG. 4 .

The process flow 600, or portions thereof, may be implemented by theenergy management unit 144 of FIG. 1 , and in particular by the software152. The process flow 600 may be implemented as one or more softwaremodules that, when executed, cause the executing device to perform theactions, functions, and operations described by the process flow 600.

The process flow 600 may interact with one or more additional processflows described herein, such as the power process flow 500 of FIG. 5 .

The process flow 600 can implement a cooling process to provide acooling service. The cooling process may be used to reduce the ambienttemperature of the facility at which the CAES system 100 is operating.

The cooling process may use heat removed from the environment topre-heat pressurized air before entering the generation subsystem # tocool the environment, such as described in FIG. 5 .

The process flow 600 can implement a heating process to provide aheating service. The heating process may be used to increase the ambienttemperature of the facility at which the CAES system 100 is operating.The heating process can use heat generated from the compression process(storage process) to heat the environment.

Heating and cooling services may be provided to the facility, at leastin part, by the HVAC system 136.

The energy management unit 144 receives HVAC data 602 as input to theprocess 600. The HVAC data 602 is stored in memory.

The HVAC data 602 includes service type data, total capacity requirementdata (e.g. in ekWh), and rate of delivery requirement data (flow rate).The service type data includes a service type, which may be a coolingservice or a heating service.

At 604, the energy management unit 144 analyzes the HVAC data 602 anddetermines whether to initiate a cooling process 606 or a heatingprocess 608. The determination 604 may be based on the service typedata. For example, if the service type data indicates a cooling service,the determination 604 may initiate the cooling process 606.

At 610, the cooling process 606 engages with the power discharge processof the CAES system 100. This includes initializing the discharge processin which air is decompressed in order to provide cooling.

Generally, the power discharge process of the CAES system 100 is similarto generation process 518 of FIG. 5 and involves generating power usingcompressed air stored in the compressed air storage 108. The compressedair 114 is released from the air storage 112, preheated using heat 110from the TES 106, and provided to the generator subsystem 126. This mayinclude using removed heat removed from the environment to preheatpressurized air 114 before entering the turbine 134.

At 612, the energy management unit 144 computes equivalent power flowoutput requirements. The equivalent power flow output requirements datacan be computed based on a power rating of the turbine and the durationit needs to run and the equivalent compressed air flow (m{circumflexover ( )}3/s) that needs to enter the turbine which needs to bepreheated (absorb the heat from the environment which results cooling).The energy management unit 144 sends a request to turn on the dischargeprocess. The equivalent power flow output requirements includes a powerflow output required to provide the requested cooling service (i.e. apower flow output provided by the power subsystem 418 to provide thedesired cooling service).

Once the request generated at 612 is sent, a power data input 616 isused in an available discharge capacity determination at 618. The powerdata input 616 is the calculated power flow data from 612.

The determination at 618 includes determining whether there is anydischarge capacity available in the pressure vessel 112 using theequivalent power flow output requirement data 612 and power data input616. The determination 618 is performed by the energy management unit144. The discharge capacity is the amount of air which should bedecompressed in order to compensate for the cooling shortage in thesystem. The discharge capacity is calculated based on the volume,pressure, and temperature of the stored compressed air.

If it is determined at 618 that discharge capacity is not available inthe pressure vessel 112, the request is denied. If the request isdenied, the energy management 144 unit determines that required coolingshould be provided by the facility HVAC system. The energy managementunit 144 may communicate with the facility HVAC system to facilitate theprovision of cooling.

If it is determined at 618 that discharge capacity is available in thepressure vessel 112, at 622, the energy management unit 144 determineswhether it is economical to use the available discharge capacity. Forexample, if the stored high-pressure air is decompressed just for thesake of cooling generation, then there might not be enough capacity leftin the system when electricity is required. As a result, the energymanagement unit 144 determines whether to use the compressed air toprovide cooling or save the compressed air for electricity generationbased on economic factors. The economic factors may be represented inthe system by economic factor data stored at the energy management unit144.

If it is determined at 622 that using the available discharge capacityis not economical, the request is denied.

If it is determined at 622 that using the available discharge capacityin the pressure vessel 112 is economical, the process flow 600 proceedsto 626.

At 626, the energy management unit 144 computes optimized air outflowdata. The optimized air data outflow includes an air flow rate from thepressure vessel 112 (i.e. flow of compressed air discharged from thevessel 112).

At 628, a power process is started (e.g. power process 500) using theoptimized air outflow data generated at 626 as input.

Also, at 628, the energy management unit uses the optimized air outflowdata to determine an available cooling value 630. The available coolingvalue 630 is stored as available cooling value data by the energymanagement unit 144.

The available cooling value 630 represents the portion of the optimizedair outflow determined at 626 that is available to use to provide thecooling service. The available cooling value 630 is collected from oneor more sensors 148 (e.g. thermostat) within the system and environment(facility) that are integrated or connected to the main system and theenergy management unit 144.

At 632, the heat flow from the TES 106 is adjusted based on theequivalent power flow output requirement computed at 632. This mayinclude the energy management unit 144 sending a signal to the controlequipment 150 to adjust the flow from the TES 106.

At 634, the energy management unit 144 computes a cooling load of theHVAC subsystem 136. The cooling load is stored by the energy managementunit 144 as cooling load data.

At 636, the cooling load determined at 634 is used to provide cooling tothe facility.

At 638, the cooling process 606 ends.

If, at 604, the energy management unit 144 determines that a heatingprocess 608 should be initiated, the heating process 608 engages withthe power charge process of the CAES system 100 (i.e. storage process510 of FIG. 5 ) at 642. Engaging the power charge process includesinitializing the charge process in which air is compressed in order toprovide heat.

Generally, the power charge process of the CAES system 100 is similar tostorage process 518 of FIG. 5 and involves storing energy usingcompressed air stored in the compressed air storage 108. The aircompression process generates heat 110 that can be used to heat theenvironment.

At 644, the energy management unit 144 computes equivalent power flowinput requirements and sends a request to turn on the charge process.The equivalent power flow input requirements includes a power flow inputrequired to provide the requested heating service (i.e. a power flowinput provided by the power subsystem 418 to provide the desired heatingservice).

Once the request generated at 644 is sent, power data input 616 is usedin an available charge capacity determination at 618. The power datainput 616 in this case is the calculated power flow data from 644.

The determination at 618 includes determining whether there is anycharge capacity available in the pressure vessel 112 using theequivalent power flow input requirement data 644 and power data input616. The determination 618 is performed by the energy management unit144. The charge capacity is the amount of air which should be compressedin order to compensate for the heating shortage in the system. Thecharge capacity is calculated based on the volume, pressure, andtemperature of the stored compressed air.

If it is determined at 618 that charge capacity is not available in thepressure vessel 112, the request is denied. If the request is denied,the energy management 144 unit determines that required heating shouldbe provided by the facility HVAC system. The energy management unit 144may communicate with the facility HVAC system to facilitate theprovision of heating.

If it is determined at 618 that charge capacity is available in thepressure vessel 112, at 622, the energy management unit 144 determineswhether it is economical to use the available charge capacity. Forexample, if air is compressed just for the sake of heating generation,then there might not be enough capacity left in the system when anotherservice is required. As a result, the energy management unit 144determines whether to compress air to provide heating or not based oneconomic factors. The economic factors may be represented in the systemby economic factor data stored at the energy management unit 144.

If it is determined at 622 that using the available charge capacity isnot economical, the request is denied.

If it is determined at 622 that using the available charge capacity inthe pressure vessel 112 is economical, the process flow 600 proceeds to626.

At 626, the energy management unit 144 computes optimized air inflowdata. The optimized air outflow data includes an air flow rate from thepressure vessel 112 (i.e. flow of compressed air charged into the vessel112). Optimized air inflow/outflow is based on the specific requirementsand limitations of each system at the time of operation.

At 628, a power process is started (e.g. power process 500) using theoptimized air inflow data generated at 626 as input.

Also, at 628, the energy management unit 144 uses the optimized airinflow data to determine an available heating value 646. The availableheating value 646 is stored as available heating value data by theenergy management unit 144. The available heating value 646 is collectedfrom one or more sensors 148 (e.g. thermostat) within the system andenvironment (facility) that are integrated or connected to the mainsystem and the energy management unit 144.

The available heating value 646 represents the portion of the optimizedair inflow determined at 626 that is available to use to provide theheating service.

At 648, the heat flow to the TES 106 is adjusted based on the equivalentpower flow input requirement computed at 644. This may include theenergy management unit 144 sending a signal to the control equipment 150to adjust the flow to the TES 106.

At 650, the energy management unit 144 computes a heating load of theHVAC subsystem 136. The heating load is stored by the energy managementunit 144 as heating load data. The heating load is the amount of heatrequired by the facility HVAC system due to heat shortage in thefacility.

At 652, heating is provided to the facility by the HVAC subsystem 136based on the heating load determined at 650.

At 638, the heating process 608 ends.

Referring now to FIG. 7 , shown therein is a process flow for apneumatic process 700 implemented by a CAES system, according to anembodiment. The process flow 700 may be the pneumatic process 444 ofFIG. 4 .

The CAES system may be the CAES system 100 of FIG. 1 . The process flow700, or a portion thereof, may be implemented by the energy managementunit # of FIG. 1 . The process flow 700 may be implemented as one ormore software modules that, when executed, cause the executing device toperform the actions, functions, and operations described by the processflow 700.

The process flow 700 may use compressed air discharged from thecompressed air storage 108 to power an end-use device (e.g. end-usedevice 142 of FIG. 1 ). The end-use device 142 may be a device that usescompressed air to operate, such as tool, device, or system (e.g.compressed air tool used in manufacturing).

The process flow 700 may control a process wherein compressed air 114that is discharged from the air storage 108 bypasses the [generationsubsystem 126 (turbine 134) and is delivered to the end-use device 142for use.

The bypass may be effected by the flow transportation subsystem 116(e.g. valves 120) of FIG. 1 , including control equipment 150 involvedin the operation thereof. The flow transportation subsystem 116 fluidlyconnects the air storage 108 to the end-use device 142 and includes abypass mechanism for effecting the transportation of the compressed air114 from the air storage 108 to the end-use device 142.

Process flow 700 uses pneumatic data 702 as an input. The pneumatic data702 includes total capacity requirement data (which may be in ekWh) andrate of delivery requirement data (flow rate). The pneumatic data isstored by the energy management unit 144. The pneumatic subsystem is theintegration point with the facility compressed air supply system. Thetotal capacity represents the available compressed air in the storage108 and is defined in terms of volume and pressure. The rate of deliveryrequirement data represents the flow of required compressed air (whichmay be in m³/hr).

At 704, the process flow 700 engages with a CAES power dischargeprocess, such as the generation process 518 of FIG. 5 . At this stage,discharged air 543 from air storage 534 may start bypassing turbine 544of the generation subsystem 126. Under normal circumstances, thedischarge process includes discharging compressed air from the airstorage tank 534 and using the discharged air 543 as input to thegeneration subsystem 126 to generate power 546.

At 706, the energy management unit 144 computes equivalent power flow(which may be in kW) output requirements. The equivalent power flowoutput requirements is stored as equivalent power flow outputrequirements data in memory of the computing device 146. The equivalentpower flow output requirements may be determined by using the pneumaticdata 702 to compute a power flow output value representing the powerflow needed from the discharge process to provide the requiredcompressed air 144. The power flow output data is recognized and used bythe generation subsystem 126 to provide power flow.

Using the computed equivalent power flow output requirement generated at706, a request is sent.

Upon sending the request, a power data input 710 (which may be in kW) isused in a pressure vessel discharge capacity determination at 712. Thepower data input 710 by energy management unit 144. The power data 710is the output of the computation at 706.

At 712, the power data input 710 is used to determine whether there isdischarge capacity available in the pressure vessel 112. Dischargecapacity represents compressed air that is stored in pressure vessel 112and available for discharge and use. Pressure vessel discharge capacitymay be stored as discharge capacity data by the energy management unit144. Discharge capacity data may be collected using sensors 148 of theenergy management unit 144 (e.g. a sensor 148 of the pressure vessel 112configured to measure the discharge capacity of the pressure vessel 112,for example at constant intervals).

If discharge capacity is not available in the pressure vessel 112, therequest is denied.

If discharge capacity is available in the pressure vessel 112, theprocess flow 700 proceeds to determination 716.

At 716, the energy management unit 144 determines whether cooling isrequired.

If cooling is not required, at 718, the energy management unit 144computes an optimized air inflow/outflow.

If cooling is required, the process 700 engages with the CAES HVACprocess (e.g. HVAC process 440, 600) at 720.

At 722, the energy management unit 144 computes a cooling load of theHVAC subsystem. The cooling load is used to compute the optimized airinflow/outflow at 718.

The computed optimized air inflow/outflow from 718 is used to start anHVAC process at 724 and a power process at 726.

Computing the optimized inflow/outflow at 718 includes generating anavailable compressed air and HVAC output 728. The available compressedair and HVAC output 728 is determined based on the size of the systemand how the system is operated.

The available compressed air and HVAC output 728 is used in computingthe equivalent power flow output requirements at 706.

At 730, the computed equivalent power flow output requirements computedat 706 is used to adjust the air flow from the pressure vessel 112. Forexample, based on the airflow that passes through the expander (turbine)and minimum heat transfer requirements, the power generated can becalculated.

At 732, the energy management unit 144 computes an economic load. Thecomputed economic load is stored as economic load data by the energymanagement unit 144.

At 734, the economic load data is used to provide compressed air.

At 736, the process 700 ends.

Referring now to FIG. 8 , shown therein is a process flow 800 for a CAESsystem design optimization, according to an embodiment. The process flow800 may be used in the design of CAES system 100 of FIG. 1 .

The process flow 800 may be implemented by a computing device and may beimplemented as one or more software modules that, when executed, causethe executing device to perform the actions, functions, and operationsdescribed by the process flow 800.

The process flow 800 starts with power data 802. The power data 802includes a power requirement (charge/discharge), a cycle duration(hours/minutes), a ramp rate/minimum requirement, and a number ofcharge/discharge cycles.

At 804, the power data 802 is used in an optimization method selection.The optimization method selection includes a selected method foroptimization of the system 100. The optimization method selection may bemade by a human interacting with the software implementing process 800(e.g. via a user interface) or automatically.

The optimization method selection include an efficiency-basedoptimization 806, an energy-based optimization 808, ora cost-basedoptimization 810. Each selected optimization 806, 808, 810 includes anassociated logic, embodiments of which are described below, that can beimplemented as one or more software modules executable on one or morecomputing devices of the system.

For efficiency optimization 806, at 812, the system is optimized formaximum system efficiency. This includes minimum losses. Maximum systemefficiency may include reducing thermo and fluid dynamic losses andoperating equipment close to maximum efficiency.

At 814, a compressor 128 size is determined according to the followingequation:

Compressor size=(Input minimum power requirement*minimum cycle duration)

At 816, a turbine 134 size is determined according to the followingequation:

Turbine size=(output minimum power requirement*minimum cycle duration)

At 818, a determination of compression/compressor 128 heat removalrequirement and turbine heat addition requirement.

At 820, if the compressor 128 heat removal requirement is greater thanthe turbine 134 heat addition requirement, then a TES 106 sizedetermination is performed at 824.

At 824, the TES 106 size determination is performed according to thefollowing equation:

TES size=Maximum input heat/thermal requirement

At 822, if the compressor heat removal requirement is not greater than(less than or equal to) turbine heat addition requirement, the TES 106size determination is performed at 826.

At 826, the TES 106 size determination is performed according to thefollowing equation:

TES size=maximum output heat/thermal requirement

For energy optimization 808, at 824, the system 100 is optimized formaximum energy storage.

At 826, an input for energy storage is determined. The input correspondsto:

Input(maximum power requirement*max cycle duration).

At 828, an output for energy storage is determined. The outputcorresponds to:

Output(maximum power*max cycle duration)

At 830, a determination is performed comparing P(input) and P(output).

At 832, if P(input) is greater than P(output), then cavern 108 size isdetermined using the following equation:

Cavern size=Input P*(maximum cycle time/max depth of discharge)

At 834, if P(input) is not greater than P(output) (i.e. less than orequal to), then cavern 108 size is determined using the followingequation:

Cavern size=Output P*(maximum cycle time/maximum depth of discharge)

For cost optimization 810, at 836, the system 100 is optimized forminimum cost. Optimizing for minimum cost may include reducing the sizeof any one or more of the turbine 134, compressor 128, cavern 108, TES106, and heat exchangers 130, 132.

At 838, an input is provided of what percentage of input/output powerrequirement needs to be covered. The input may be provided by a user oroperator of the system.

For input percentage, at 840, compressor 128 size is determined usingthe following equation:

Compressor size=(% input maximum power requirement*max cycle duration)

At 842, heat exchanger 130 size is determined using the followingequation:

Heat exchanger size=(Q in based on max flowrate and T)

At 844, TES 106 size is determined using the following equation:

TES size=maximum(input heat/thermal requirement)

For output percentage, at 846, turbine 134 size is determined accordingto the following equation:

Turbine size=(% output max power requirement*maximum cycle duration)

At 848, heat exchanger 132 size is determined according to the followingequation:

Heat exchanger size=(Q out based on max flowrate and T)

At 850, TES 106 size is determined according to the following equation:

TES size=maximum output heat/thermal requirement.

At 852, receiving inputs from the input percentage pathway and outputpercentage pathway, a determination is performed as to whether thesystem 100 exceeds any technical or operating limits. Technical oroperating limits may be stored as technical and operating limit data.

If it is determined at 852 that the system does not exceed technical oroperating limits, the conditions set (calculated) at 840, 842, 844, orat 846, 848, 850, as the case may be, are accepted by the system.

If it is determined at 852 that the system does exceed technical oroperating limits, then at 856 a component size adjustment is performedto try and bring the system within technical and operating limits. Afterperforming the component size adjustment, the size determinations at840, 842 844 and 846, 848, 850 are repeated.

Referring now to FIG. 9 , shown therein is a block diagram illustratingan energy management unit 144, in accordance with an embodiment. Theenergy management unit 144 is used by a CAES system such as system 100of FIG. 1 .

The energy management unit 144 includes an energy management serverplatform 12, which communicates with a plurality of controller devices16-1, 16-2, and 16-3 (collectively referred to as controllers 16 andgenerically as controller 16). The controllers 16 may be controllerdevices that are associated with a particular subsystem (e.g. HVAC,power, pneumatic) or component of a subsystem (e.g. compressor, storagetank, HVAC unit). The system 144 also includes a plurality of sensordevices 14, which can acquire and transmit various sensor data.

The server 12 may be computing device 146, the controller 16 may becontrol equipment 150, and the sensor device 14 may be sensors 148 ofFIG. 1 .

The server platform 12 and devices 14, 16 may be a server computer,desktop computer, notebook computer, tablet, PDA, smartphone, or anothercomputing device. The devices 12, 14, 16 may include a connection withthe network 20 such as a wired or wireless connection to the Internet.In some cases, the network 20 may include other types of computer ortelecommunication networks. The devices 12, 14, 16 may include one ormore of a memory, a secondary storage device, a processor, an inputdevice, a display device, and an output device. Memory may includerandom access memory (RAM) or similar types of memory. Also, memory maystore one or more applications for execution by processor. Applicationsmay correspond with software modules comprising computer executableinstructions to perform processing for the functions described below.Secondary storage device may include a hard disk drive, floppy diskdrive, CD drive, DVD drive, Blu-ray drive, or other types ofnon-volatile data storage. Processor may execute applications, computerreadable instructions or programs. The applications, computer readableinstructions or programs may be stored in memory or in secondary storageor may be received from the Internet or other network 20.

Input device may include any device for entering information into device12, 14, 16. For example, input device may be a keyboard, keypad,cursor-control device, touch-screen, camera, or microphone. Displaydevice may include any type of device for presenting visual information.For example, display device may be a computer monitor, a flat-screendisplay, a projector or a display panel. Output device may include anytype of device for presenting a hard copy of information, such as aprinter for example. Output device may also include other types ofoutput devices such as speakers, for example. In some cases, device 12,14, 16 may include multiple of any one or more of processors,applications, software modules, second storage devices, networkconnections, input devices, output devices, and display devices.

Although devices 12, 14, 16 are described with various components, oneskilled in the art will appreciate that the devices 12, 14, 16 may insome cases contain fewer, additional or different components. Inaddition, although aspects of an implementation of the devices 12, 14,16 may be described as being stored in memory, one skilled in the artwill appreciate that these aspects can also be stored on or read fromother types of computer program products or computer-readable media,such as secondary storage devices, including hard disks, floppy disks,CDs, or DVDs; a carrier wave from the Internet or other network; orother forms of RAM or ROM. The computer-readable media may includeinstructions for controlling the devices 12, 14, 16 and/or processor toperform a particular method.

Devices such as server platform 12 and devices 14, 16 can be describedperforming certain acts. It will be appreciated that any one or more ofthese devices may perform an act automatically or in response to aninteraction by a user of that device. That is, the user of the devicemay manipulate one or more input devices (e.g. a touchscreen, a mouse,or a button) causing the device to perform the described act. In manycases, this aspect may not be described below, but it will beunderstood.

As an example, it is described below that the devices 12, 14, 16 maysend information to the server platforms 12 and 14. For example, a userusing the device 16 may manipulate one or more inputs (e.g. a mouse anda keyboard) to interact with a user interface displayed on a display ofthe device 16. Generally, the device may receive a user interface fromthe network 20 (e.g. in the form of a webpage). Alternatively, or inaddition, a user interface may be stored locally at a device (e.g. acache of a webpage or a mobile application).

Server platform 12 may be configured to receive a plurality ofinformation, from each of the plurality of devices 14, 16.

In response to receiving information, the server platform 12 may storethe information in storage database. The storage may correspond withsecondary storage of the devices 14, 16. Generally, the storage databasemay be any suitable storage device such as a hard disk drive, asolid-state drive, a memory card, or a disk (e.g. CD, DVD, or Blu-rayetc.). Also, the storage database may be locally connected with serverplatform 12. In some cases, storage database may be located remotelyfrom server platform 12 and accessible to server platform 12 across anetwork for example. In some cases, storage database may comprise one ormore storage devices located at a networked cloud storage provider.

The server platform 12 may be a purpose-built machine designedspecifically for managing and controlling the type and amount of energystored and used by the CAES system 100. The server 12 may manage andcontrol the flow of air throughout the system 100 in order to providepower, HVAC, and pneumatic services. The server 12 may be configured tooptimize outputs of various components of the system 100 in order toreduce power demand and reduce waste energy.

Referring now to FIG. 10 , shown therein is a simplified block diagramof components of a computing device 1000, such as a server, computingdevice, mobile device or portable electronic device. The device 1000 maybe computing device 146 of energy management unit 144 or server 12 ofenergy management unit 10.

The device 1000 may be used to provide various computing functionalities(e.g. processing, storage, communication, etc.) of the energy managementunit 10, as described herein. The energy management unit 10, 144 mayinclude a plurality of computing devices 1000 communicatively connectedto one another via a communication network, such as a wide area networkor local area network.

The device 1000 includes multiple components such as a processor 1020that controls the operations of the device 1000. Communicationfunctions, including data communications, voice communications, or bothmay be performed through a communication subsystem 1040. Thecommunication subsystem 1040 may include one or more communicationinterfaces for receiving and transmitting data. Data received by thedevice 1000 may be decompressed and decrypted by a decoder 1060. Thecommunication subsystem 1040 may receive messages from and send messagesto a wireless network 1500.

The wireless network 1500 may be any type of wireless network,including, but not limited to, data-centric wireless networks,voice-centric wireless networks, and dual-mode networks that supportboth voice and data communications.

The device 1000 may be a battery-powered device and as shown includes abattery interface 1420 for receiving one or more rechargeable batteries1440.

The processor 1020 also interacts with additional subsystems such as aRandom Access Memory (RAM) 1080, a flash memory 1090, a display 1120(e.g. with a touch-sensitive overlay 1140 connected to an electroniccontroller 1160 that together comprise a touch-sensitive display 1180),an actuator assembly 1200, one or more optional force sensors 1220, anauxiliary input/output (I/O) subsystem 1240, a data port 1260, a speaker1280, a microphone 1300, short-range communications systems 1320 andother device subsystems 1340.

In some embodiments, user-interaction with the graphical user interfacemay be performed through the touch-sensitive overlay 1140. The processor1020 may interact with the touch-sensitive overlay 1140 via theelectronic controller 1160. Information, such as text, characters,symbols, images, icons, and other items that may be displayed orrendered on a portable electronic device generated by the processor 102may be displayed on the touch-sensitive display 118.

The processor 1020 may also interact with an accelerometer 1360 as shownin FIG. 1 . The accelerometer 1360 may be utilized for detectingdirection of gravitational forces or gravity-induced reaction forces.

To identify a subscriber for network access according to the presentembodiment, the device 1000 may use a Subscriber Identity Module or aRemovable User Identity Module (SIM/RUIM) card 1380 inserted into aSIM/RUIM interface 1400 for communication with a network (such as thewireless network 1500). Alternatively, user identification informationmay be programmed into the flash memory 1090 or performed using othertechniques.

The device 1000 also includes an operating system 1460 and softwarecomponents 1480 that are executed by the processor 1020 and which may bestored in a persistent data storage device such as the flash memory1090. Additional applications may be loaded onto the device 1000 throughthe wireless network 1500, the auxiliary I/O subsystem 1240, the dataport 1260, the short-range communications subsystem 1320, or any othersuitable device subsystem 1340.

For example, in use, a received signal such as a text message, an e-mailmessage, web page download, or other data may be processed by thecommunication subsystem 1040 and input to the processor 1020. Theprocessor 1020 then processes the received signal for output to thedisplay 1120 or alternatively to the auxiliary I/O subsystem 1240. Asubscriber may also compose data items, such as e-mail messages, forexample, which may be transmitted over the wireless network 1500 throughthe communication subsystem 1040.

For voice communications, the overall operation of the portableelectronic device 1000 may be similar. The speaker 1280 may outputaudible information converted from electrical signals, and themicrophone 1300 may convert audible information into electrical signalsfor processing.

Referring now to FIG. 11 , shown therein is a CAES system 1100 includingelectric heating for promoting a rapid response, according to anembodiment. The CAES system 1100 is a variant of the CAES system 100 ofFIG. 1 . Components of the system 1100 having counterpart componentsperforming the same or similar function in the system 100 of FIG. 1 aregiven the same reference numbers as in FIG. 1 . Components of the system100 of FIG. 1 not shown in FIG. 11 may or may not be present.

The CAES system 1100 provides a rapid response (ramp-up) for a CAESsystem using electric heating. The electric heating provides an improvedor enhanced heating mechanism (e.g. over that in systems 100 or 200 ofFIGS. 1 and 2 ) for the CAES system 1100 that may reduce the delay inheating the cold pressurized air before entering the turbine for powergeneration.

The system 1100 includes turbine 134. The turbine 134 starts, initiatingthe heat-up process.

The system 1100 includes a pump 1102. The pump 1102 may be a componentof the fluid transport subsystem 116 of FIG. 1 . Fluid conduit 118 afluidly connect the TES unit 104 to the pump 1102 and fluid conduit 118b fluidly connects the pump 1102 to the heat exchanger 132.

The pump 1102 starts circulation of hot flow from the TES unit 104. Thehot flow is carried from the TES unit 104, through the pump 1102 and tothe heat exchanger 132 via fluid conduits 118 a, 118 b.

The system 1100 includes air tank 108 which provides cold pressurizedair to the heat exchanger 132 via fluid conduit 118 c. Fluid conduit 118c fluidly connects the air tank 108 to the heat exchanger 132.

The hot flow received at the heat exchanger 132 from the TES unit 104passes through the heat exchanger 132, heating the cold pressurized airexiting the air tank 108 and arriving at the heat exchanger 132.

Heated air exits the heat exchanger 132 and travels via fluid conduit118 d to an electric heater 1104. The electric heater 1104 is powered bya battery 1106.

The heater 1104 heats up the received heated air flow and outputs thefurther heated airflow to turbine 134 via fluid conduit 118 e.

The turbine 134 generates power from the further heated airflow.

The system 1100 also includes a first temperature sensor 148-1 and asecond temperature sensor 148-2 for recording temperature measurements.

The first temperature sensor 148-1 reads a temperature of the air tank108 output, for example at 1108, prior to processing by the heatexchanger 132. The first temperature sensor 148-1 may thus be positionedat or near 1108.

The second temperature sensor 148-2 reads a temperature of the heatexchanger 132 output, for example at 1110. The second temperature sensor148-2 may thus be positioned at or near 1110.

The first and second temperature sensors 148-1, 148-2 are connected tocontrol unit 150 via communication links 1112 a, 1112 b, respectively.The first and second temperature sensors 148-1, 148-2 send collectedtemperature measurement data or signals to the control unit 150 via thecommunication links 1112 a, 1112 b.

The control unit 150 is configured to determine an appropriate (e.g.optimum) control signal based on the received temperature measurementsignals from the first and second temperature sensors 148-1, 148-2.

The temperature measurement of the first temperature sensor 148-1 (T1measurement) is used by the control unit 150 to control the pump 1102for an optimized hot air mass flow rate. Accordingly, the control unit150 may determine a pump control signal for the optimized hot air flowrate and send the pump control signal via a communication link 1114connecting the control unit 150 to the pump 1102. The pump 1102 isconfigured to automatically adjust an operating parameter according tothe received pump control signal. Adjusting the operating parameter ofthe pump 1102 adjusts the flow rate of the hot air from the TES unit 104to the heat exchanger 132.

The temperature measurement of the second temperature sensor 148-2 (T2measurement) is used by the control unit 150 to control a heat output ofthe electric heater 1104. For example, the control unit 150 may controlthe heat output of the electric heater 1104 to a desired temperature(T). Accordingly, the control unit 150 may determine an electric heatersignal based on the received T2 measurement and send the electric heatersignal via a communication link 1116 connecting the control unit 150 tothe heater 1104. The electric heater 1104 is configured to automaticallyadjust an operating parameter according to the received electric heatersignal. Adjusting the operating parameter adjusts the heat output of theelectric heater 1104. Generally, as the T2 measurement trends to thedesired temperature, the electric heater 1104 gradually decreases itsheat output (according to the received heater control signal). Theheater 1104 may shut down when the T2 measurement reaches the desiredtemperature. In such a case, the control unit 150 receives a T2measurement from the second temperature sensor 148-2 via thecommunication link 1112 b and determines that the T2 measurement hasreached the desired temperature (the desired temperature value beingstored at or otherwise accessible to the control unit 150) and sends aheater control signal which, when received by the heater 1104, causesthe heater 1104 to shut down.

The system 1100, and in particular the electric heater 1104 and relatedcontrol mechanism, may advantageously provide for a rapid response toquickly heat up the airflow, reducing the time the system 1100 takes togo online. For example, in embodiments without the electric heater 1104(and related sensing and control), the system 1100 may take 10 to 15minutes to come online to get the air to be input to the generator 134to a temperature where the generator 134 can be started (e.g. to atemperature where you can start to put a load on it). Advantageously,the electric heater 1104 can help get the air to the appropriatetemperature quickly, avoiding some time delay, and once the air reachesthe desired temperature the electric heater 1104 can be turned off. Thesystem 1100 may thus provide an improved response time.

While the above description provides examples of one or more apparatus,methods, or systems, it will be appreciated that other apparatus,methods, or systems may be within the scope of the claims as interpretedby one of skill in the art.

1. A system for energy storage, the system comprising: athermomechanical-electrical conversion subsystem for converting energyformats including: a storage subsystem including a fluid compressor anda first thermal energy exchanger, the storage subsystem for compressionof a fluid to generate compressed fluid and thermal energy; a generationsubsystem including a power generator and a second thermal energyexchanger, the generation subsystem for generating power from thecompressed fluid and the thermal energy; a mechanical and thermalstorage unit for storing energy formats including: a pressure vessel forstoring the compressed fluid; and a thermal energy storage for storingthe thermal energy generated by the fluid compression and for providingthe thermal energy to the generation subsystem for generating power. 2.The system of claim 1, wherein the energy formats include any two ormore of electricity, thermal energy, and pneumatic energy.
 3. The systemof claim 1, wherein the energy formats include electricity, thermalenergy, and pneumatic energy.
 4. The system of claim 1, wherein thecompressed fluid is compressed air, and wherein the energy formatsinclude electricity and at least one of thermal energy and pneumaticenergy.
 5. The system of claim 1, wherein the compressed fluid iscompressed air and the compressed air has a pressure between 4 MPa and70 MPa.
 6. The system of claim 1, wherein the pressure vessel is locatedabove ground and is composed of high-strength steel or composite.
 7. Thesystem of claim 1, wherein the pressure vessel is located underground ina borehole.
 8. The system of claim 7, wherein the borehole includes afirst vertical segment housing the pressure vessel and a second verticalsegment housing the thermal energy storage.
 9. The system of claim 1,wherein the pressure vessel comprises an outer casing enclosing an innercompartment for storing the compressed fluid, and wherein the outercasing is composed of a thermally insulating material.
 10. The system ofclaim 1, wherein the power generator is a microturbine having a capacityrange of 250 kW to 25 MW.
 11. The system of claim 1, wherein the thermalenergy storage comprises at least one of an underground thermal energystorage using ground as storage medium, a phase change storage, athermo-chemical storage, and a cool thermal energy storage.
 12. Thesystem of claim 1, further comprising an end-use device which is fluidlyconnected to at least one of the thermal and mechanical storage unit andthe thermomechanical-electrical conversion subsystem via a fluidtransportation subsystem, and wherein the end-use device receives anenergy format generated by the system.
 13. The system of claim 12,wherein the energy format received by the end-use device is electricity,thermal energy, or pneumatic energy.
 14. The system of claim 12, whereinthe end-use device is an air treatment unit or a process heating unit,and wherein the energy format received by the end-use device is thermalenergy.
 15. The system of claim 12, wherein the end-use device is acompressed air-powered device, and wherein the energy format received bythe end-use device is pneumatic energy.
 16. The system of claim 1,wherein the system operates at a facility having a demand range of 1 MWto 5 MW.
 17. The system of claim 1, further comprising a flowtransportation subsystem for fluidly connecting thethermomechanical-electrical conversion subsystem and the mechanical andthermal storage unit and transportation of a working fluid therebetween.18. The system of claim 1, further comprising an energy management unitincluding a computing device in communication with at least one controldevice, the energy management unit configured to: monitor energy formatdemand data for at least one energy format; determine a controloperation based on the energy format demand data; and generate controldata encoding instructions for performing the control operation, whereinthe control data, when received by the at least one control device,causes the control device to perform at least one of: adjusting a flowof a working fluid between the mechanical and thermal storage unit andthe thermomechanical-electrical subsystem; and adjusting an operatingparameter of at least one of the storage subsystem and the generationsubsystem.
 19. The system of claim 1, wherein the compressed fluid iscompressed air, and wherein the system further comprises an electricheater for heating the compressed air after being heated by the secondthermal energy exchanger and prior to entering the power generator. 20.The system of claim 19, further comprising: a first temperature sensorfor recording a first temperature measurement of the compressed airprior to entering the second thermal energy exchanger; a secondtemperature sensor for recording a second temperature measurement of thecompressed air after passing through the second thermal energyexchanger; and a control unit for: receiving the first and secondtemperature measurements from the first and second temperature sensors,respectively; controlling flow of the thermal energy from the thermalenergy storage to the second thermal energy exchanger based on the firsttemperature measurement; and controlling a heat output of the electricheater based on the second temperature measurement. 21-35. (canceled)